Homework on Stale Blocks

Blockchain and Bitcoin 101
#1504

When two miner solve a block at the same time then the block chain will split. Both branches will be confirmed and valid until the next block is added to the branch with the most proof of work.

A stale block is the branch of the blockchain that will be dropped and added to the mempool.

A stale block is formed when the block is dropped in favor of a block chain arrangement with greater proof of Work.

It is better wait at least for 6 confirmations because your transaction may get dropped and sent back to the mempool.

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#1505
  1. Solving the block leads to a temporary mix-up on the blockchain network, as the nodes try to decide which block of the two newly identified blocks it wants to accept.
    the block with the larger proof of work (POW) gets accepted into the blockchain. The other block, with a smaller proof of work, is discarded from getting added to the blockchain and is termed as an orphan block.
    2 blockchain network due to a time lag in the acceptance of the block in question into the blockchain, as compared to the other qualifying block stale blocks are valid and verified blocks rejected by not being longest chain
    3.Stale Blocks are blocks that are no longer part of the current best blockchain because they were overridden by a longer chain. Longest chain wins geographical located nodes
  2. best interest of blockchain networks to pace wait for 6 confirmation themselves in such a way to avoid the reverse action to mempool and production of stale blocks
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#1506
  1. What happens in the bitcoin network when two miners solve a block at the same time?

Each miner propagates the nodes nearest them first, so the chain forks whilst both are spreading. Another block will be solved based on one of these blocks and the PoW will increase on this specific path of the fork. This longer block will then propagate around the network to all nodes eventually. The block that was not included in this version of the chain will disappear and all the transactions in it will return to the mempool.

  1. What is a stale block?

This is a block that has been built on a block that has formed a fork in the blockchain (see answer to 1 question 1). This part of the fork has the lesser Proof of Work and disappears with all the transactions in all of the associated blocks returning to the mempool.

  1. How do stale blocks occur?

They occur when the chain forks because two (or more) miners create different, blocks at the exact same time. Other blocks then get added, but it is the chain with the greatest Proof of Work that the network takes. Stale blocks occur on the other other chain and transactions get returned to the mempool as that version of the chain disappears.

  1. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?

Best practice is to wait for 6 confirmations to be sure that the block with the specific transaction in it is confirmed. It is possible that due to the way the chain gets blocks added and takes time to propagate around the network, that it may, in fact be part of a fork that has the lesser Proof of Work and will disappear with the transaction (and all the other transactions on that fork of the chain) going back into the mempool.

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#1507
  1. There is a temporary fork in the chain
  2. A stale block is one where the transactions are put back into the mempool
  3. Stale blocks occur when one of the blocks in the fork receives more proof of work and continues. The stale block is dropped because the other block is longer.
  4. To make sure that your transaction isn’t part of a stale or orphan block
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#1508
  1. When two miners solve a block at the same exact time, two equal chains are created.
  2. A stale block is a block that was in the blockchain at one time but got dropped due to the existence of a longer chain.
  3. Stale blocks occur due to the potential production of two blocks at the same time. When this happens and both blocks are being further mined, the longer block becomes the verified truth and the shorter block then becomes dropped into the mempool.
  4. Ideally it is good to wait for 6 more block confirmations to confidently add a transaction. This practice is to reduce the chance that there may be another blockchain that would be longer and invalidate yours.
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#1509
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#1510

1. What happens in the bitcoin network when two miners solve a block at the same time?
The longer blockchain will be chosen by the network - longer meaning the one with more proof of work at the appropriate difficulty, it's not just dependent on how many blocks there are. The block not included will be dropped and will become a "stale block".

2. What is a stale block?
A valid block that was dropped because a longer blockchain (version of the truth) without that block on it was accepted by the network.

3. How do stale blocks occur?
When many people are mining at once there is a chance that multiple miners find the nonce at the same time, and different versions of the blockchain start circulating amongst different nodes (since they each will have likely mined different blocks). Since the system only accepts one version of the blockchain going forward, one of these solutions will win out, resulting in the other one becoming a "stale block."

4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
It is best practice to wait for 6 confirmations (your block being added to the blockchain and then six other blocks after) since then you can be sure that this is the accepted version of the blockchain going forward. Otherwise your block with its "confirmed transactions" could be beaten out in favor of a different version of the blockchain with more proof of work (one that does not include your block).

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#1511
  1. The miner whose block has a longer chain of confirmations/other blocks supporting becomes the valid block and other miner’s block gets dropped
  2. A stale block is the one which gets dropped in above situation(point 1)
  3. Stale blocks occur when different nodes of network have solved blocks from 2 or more different miners in approximately same time. Only one miner’s block finally makes it to blockchain, others get dropped.
  4. One should wait for at least 6 confirmations else your transaction might end up in a stale/orphaned block and the transaction will then be invalid.
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#1512
  1. The block is always propagated to the closest nodes in order, this can create two different blockchains with two different “truths”.
  2. Stale blocks are blocks that were in the blockchain at one time but then got dropped because there is a longer version of the chain. All transactions from the stale block go back to the mempool.
    3.When two miners solve a block in the same time.
  3. After 6 confirmation, it is sure that the block hasn’t been dropped.
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#1513

  1. it means that, temporarily, there will be two versions of the blockchain in the network until one version eventually “wins” by getting more blocks added than the other version.

  2. it is a valid block that is dropped from the network.

  3. When there is more than one version of the blockchain on the network, only one version will remain, while the other will be dropped. When one version is confirmed, the other version, along with its newly create blocks (stale blocks), are dropped, and the transactions in them go back to the mempool.

  4. Because mining occurs very fast, six confirmations is a good, conservative number to wait.

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#1514
  1. When two miners solve a block at the same time then as far as the nodes are concerned they are both valid and will continue using their native copy until a new block or longer chain is discovered
  2. A stale block is a block that was once part of the blockchain but got replaced by a different copy of the blockchain somewhere along the way.
  3. Stale blocks occur when two miners solve a block at the same time and propagate it around all nodes so that there are two copies of the blockchain on nodes around the world, when another block is completed and integrated into the blockchain and is sent out again using one of the valid blockchain copies all nodes will accept this new, longer version of the blockchain. The blocks accepted on the other version of the blockchain become stale blocks.
  4. It is important to wait for more than one block to be confirmed when making transactions for safety, to remove the possibility of having the block your transaction was confirmed in becoming orphaned or stale.
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#1515

  1. If both blocks are solved at the same time, they both begin propagating to nodes, competing with eachother. Eventually another block will be created based off of one of these competing blocks, once that happens that will be the longest blockchain and will ‘win’ over the other block.

  2. A stale block is a completedvblock that is dropped from the network and all of its transactions returned to the mempool.

  3. A stale block occurs when there are more than one valid blocks competing, the losing block is then dropped.

  4. Due to the length of time it takes for new blocks to propagate throughout the network, it’s possible a block your transaction took place on will be dropped and returned to the mempool.

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#1516

  1. then this will create a situation where both versions will spread their blocks which results in two new block chains, whenever the next block is added, then whichever version is longer in blockchain length and has appropriate level of difficulty, will win out. The other version and all consecutive blocks are dropped.

  2. Stale blocks are the blocks dropped when one version loses out to the real version of the blockchain.

  3. Stale blocks occur when a chain is dropped and replaced with a better and more accurate version of the blockchain.

  4. Waiting for 6 or more confirmations helps lower the likelihood of a block being dropped and orphaned.

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#1517

  1. When two miners solve a block at the same time there will be two blocks being propagated in the network. A set of notes will have received one block and the other set the other block.

  2. A stale block is a dropped block. One of the two blocks produced at the same time but then no other block is attached to it. If the second block gets a block attached first then the first block is dropped, because the network only recognizes the longest chain, it becomes dropped (stale or orphaned).

  3. Stale block occurs if it is not confirmed within 10 minutes the block time.

  4. It is important to wait for more than one block to be confirmed when sending or receiving a transaction in order to minimized the block becoming stale and being dropped.

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#1518

Why would block time have any influence if a block gets dropped or not? Check your first two answers again and think it through :wink:

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#1519
  1. What happens in the bitcoin network when two miners solve a block at the same time?
  • Chain will splitt and both block’s will start propagating through the network until one of the chains become shorter.
  1. What is a stale block?
  • A discarded block on an shorter chain.
  1. How do stale blocks occur?
  • They occur when two blocks are mined and added at the same time.
  1. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
  • In case of two blocks being mined simultaneously your transaction might be in the block witch are discarded. (on the shorter chain).
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#1520

1- The situation arises where a complete approved block gets dropped or kicked out into the mempool which leads to what is called orphaned or stale block.
2-stale block is where a complete approved block ( shortest blockchain/version of truth) from a miner gets kicked out failing to compete over a longer chain of blocks (with another version of truth) within more transactions and transaction fees which produced from another miner that has been accepted larger number of nodes in the network
3- simultaneous occurrence of POW or version of truths from two miners where the the most acceptance rate from node network happens to a specific version of truth or POW which also eventually propagates faster as well in the network
4- Miners get more incentives and rewards for a longer blockchain / higher acceptance rate from node network , which in turn secures the network and helps the block to be approved and propagated faster in approx 10 mins or less

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#1521

  1. Both blocks are equally valid until a miner produces the next block. When that miner adds the new block onto one of the old blocks, it validates one of the blocks, and orphans the next block. For our purposes, orphaning is the same as creating a stale block.

  2. A stale block is a valid block that did not propagate the blockchain, (i.e., a miner attached a block onto a different chain), and therefore is no longer in use in the whole blockchain.

  3. Stale blocks occur when two miners solve a block at the same time, and then another miner solves the blockchain and builds onto the other block (from the stale block).

  4. It is important to wait for more than one block to be confirmed when conducting a transaction, because you must be certain that your transactions were not dropped from the chain and sent back to the mempool.

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#1522
  • What happens in the bitcoin network when two miners solve a block at the same time?

Both are accepted as valid truthful blocks to be part of the blockchain .

  • What is a stale block?

A valid block that is rejected by the network and placed back into the mempool.

  • How do stale blocks occur?

When a block from a miner is rejected due to not being part of the longer blockchain, and it is placed back into the mempool.

  • Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?

The network accepts the longest blockchain and therefore waiting those 10 minutes to have everyone accept the block and continue mining another 6 (at least) so that your block can be accepted as the true one and not be rejected.

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#1523
  1. What happens in the bitcoin network when two miners solve a block at the same time?
  2. What is a stale block?
  3. How do stale blocks occur?
  4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?

1)they start to compete , the one which chain is longer wins
2)if 2 versions of the blockchain are competing with each other , which is longer and one version loses , the blocks mined in that chain become orphaned and the transactions go again into the mempool , as everyone has to accept the longest chain as a winner inthis competition
3)they occur as a result of the compititional process described above.
4)because the transaction can be part of an orphaned block and the transactions have to go back into the mempool again .

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